What is an attribution window?

An attribution window, also called a conversion window, is a defined period of time in which a publisher can claim that a click or impression led to an install. For example, if an advertiser sets an attribution window of 5 days and a user clicks on a publisher’s ad and then installs within those 5 days, then the publisher receives the credit for the installation.

Mobile measurement partners (MMPs) use last-click attribution as their attribution model. This means, in the example above, the publisher will receive payment as long as they can claim the last click before an install.

Why are attribution windows important?

Attribution windows help advertisers and publishers understand when a conversion takes place. Often, there is a gap between the time someone views an ad for an app and when they install it.

Allowing for potential gaps between viewing an ad and installing an app prevents users from being mistaken as organic instead of being paid for, which would cause publishers to lose money. 

You can also use attribution windows to test different networks. For example, if you have a finance app and want to run a video campaign with two different ad networks (A and B), where A is a trusted network and B is a new one. If you want to test the performance of Network B using a campaign based on probabilistic matching, you could limit their attribution window to one hour and leave Network A at the default 24 hours, thus strictly controlling what traffic can be claimed by Network B. 

What is an optimal attribution window? 

The optimal length for an attribution window should be determined based on the campaign objective. For example, an advertiser running an install campaign boosted by “seen and gone” formats (such as banner ads) might want a shorter window because while thousands of people might briefly view an ad, an impression-based form is unlikely to drive an installation 5 days later. 

On the other hand, advertisers running a campaign that prompts interaction — through a playable ad, for example — may want a longer attribution window. 

Furthermore, if an advertiser secures a prime position in an app and wants to evaluate its long-term value, then a 21- or 30-day window would help them determine if it delivered the desired results.